Dear John Schutkeker:

On May 2, 11:56 am, John Schutkeker
wrote:
Bruce Scott TOK ] wrote :
....
Are you interested in Navier Stokes fluids (i.e.,
gasdynamics) or actual liquids where the quantum
physics determines the microproperties?

AFAIK, Navier-Stokes (NS) is just a momentum
balance equation, making me ask, since when don't
liquids obey the same force balances on a
differential fluid element as gasses?

Navier Stokes works with viscosity, which is an energy loss term.

If that's true, what momentum equation replaces
NS, in the incompressible liquid case you mentioned?

It depends you your simplifications from NS.

There should be only one equation, and it's NS,
although the viscosity may be a complicted function,
rather than a constant.

Having viscosity a function of the flow field only makes it more
complex. But you are already talking about an insoluble PDE without
simplifying assumptions. So it just adds to computation time for a
numerical solution.

But it should still be NS, shouldn't it?

I believe so, yes.

I'm interested in a fluid whose properties are hardly
even known: planetary mantles and cores, like Earth
and Enceladus. Nobody knows exactly what are
those fluid properties, raising a whole 'nother theory
question that I plan to gloss over.

I'm thinking that under such high pressures,
Enceladus' "mantle" may be a highly viscous liquid,
which might be something like a solution of liquids
like N2, NH3, and CH4, etc. Unfortunately, it may
also be the mixture of solid/liquid phases that we
colloquially know as "slush."

Any permanent features on the surface? Something like the "Great Red
Spot" of Jupiter notwithstanding...

David A. Smith